On Friday Whole Foods announced it would begin requiring labeling of all genetically modified foods sold in its stores, making it the first retail store in the United States to do so.

According to The New York Times A. C. Gallo, president of Whole Foods, said the new labeling requirement would probably take five years to go into effect. Products containing GMOs are already labeled in Whole Foods' Great Britain stores, since GMO labeling is required in the European Union.

This decision has huge ramifications for proponents of GMO labeling, and it has intensified the debate over genetically modified ingredients. Proponents of labeling point to a few studies done in rats that say bioengineered food can be harmful, and contend that consumers have a right to know about the ingredients in the food they eat. (It should be noted that some scientists questioned the study's findings and methodology.) Those against labeling say that there are no strong scientific findings (see above) showing that genetically modified foods caused health or safety issues, and thus labeling was unnecessary and a form of fear-mongering.

Public opinion is strongly in favor of GMO labeling, as a 2012 election poll showed. According to the Times, more than 90 percent of respondents said they were in favor of labeling genetically modified foods, with 93 percent of Democrats and 89 percent of Republicans voting for it.